Later, at the Khitomer Conference being held near the Romulan border, West disguised himself as a Klingon and attempted to assassinate the Federation President. Taking position behind a large window and taking aim at the president with a sniper rifle, West prepared to fire, but missed at the last instant as Captain Kirk pushed the president out of the way. After Captain Spock announced that another conspirator, LieutenantValeris, was in custody, West took aim at Valeris, intending to eliminate her to prevent her from testifying, but was stopped when Montgomery Scott burst through the door, shooting him with a phaser. West was thrown through the glass and fell to the ground, dying on impact. Examining the body, Colonel Worf noticed that West's blood was not Klingon, and unmasked him, revealing West's role in the conspiracy. (Star Trek VI: The Undiscovered Country)

West never actually appeared in the theatrical version of Star Trek VI, since his scenes were deleted. However, he can be seen on the VHS and DVD releases of the movie, but is not listed in the cast credits at the end of the VHS or DVD. Rene Auberjonois was under the impression West's involvement in the film had been completely cut until he learned, from an audience at a Star Trek convention, that it had been reinstated in the VHS version. (Star Trek - Where No One Has Gone Before, paperback ed., p. 173)

In 2009, The Undiscovered Country was re-released on DVD, omitting the West scenes, as it was the first DVD release of the theatrical cut. The theatrical cut is also the only version released to date on Blu-ray.

While identified in dialogue as a "colonel", West wore the uniform of a Starfleet vice admiral.